Electric motor construction



Decll, 1962 c. R. CNTONWINE 3,068,389

ELECTRIC MOTOR CONSTRUCTION Filed Oct. 3, 1958 2 Sheets-Sheet 1 Dec. 11, 1962 c. R. cANToNwlNE 3,068,389

` `ELECTRIC MOTOR CONSTRUCTION Filed Oct. 5, 1958 2 Sheets-Sheet 2 sUnite States Patent 3,068,389 ELECTRIC MOTOR CNSTRUCTIN Charles R. Cantonwine, Rte. 1, BOX 296, Het Springs, Ark. Filed ct. 3, 1958, Ser. No. 765,23 9 Claims. (Ci. S18-22h) This invention relates to motors in general and more particularly to improved means for starting and running alternating current motors which enables such motors to have reduced starting current without requiring separate impedance devices for starting purposes and without loss of starting torque and furthermore to operate having increased output.

in my co-pending patent application, Serial No. 661,634, fried May 2'7, 1957, there is described a relatively simple motor construction which uses all of the windings in the motor for starting and for running, thereby increasing the torque and the efficiency.

in the past, it has been the practice to provide alternating current split-phase motors with a high resistance and low inductan-ceistarting winding and a running winding of high inductance and low resistance in order to provide means for shifting the phase of the starting current to provide starting torque. Due to the small angle of phase shift that is produced during starting in the known constructions, the total locked rotor current is almost the numeric sum of the current flowing through the main and starting windings. ri`his means that a relatively high starting current is required and this in turn limited the use of spiit-phase motors to the lower ratings in the fractional horsepower range and forced the use of more costl motor constructions in the larger sizes and also in light and middle starting torque applications. The present invention overcomes these objectionable features of known split-phase motors by providing a relatively simple motor construction having a starting torque that equals or exceeds that provided by known split-phase motors, and this is accompiished with even less starting current.

it is therefore a principal object of this invention to provide an alternating current motor having low starting current without requiring the use of impedance devices and without reducing the capacity and ei'liciency of the motor.

Another object of the invention is to increase the eiiiciency of alternating current motors by employing all of the windings thereof during starting and running.

Another object is to employ transformer action between windings of an alternating current motor to produce phase shift and starting torque.

Another object of this invention is to provide an alternating current motor capable of producing an output limited only by the operating conditions of the motor and not by conditions imposed thereon by the starting requirements.

Another obgect of the invention is to reduce magnetic vibration and noise in alternating current motors especially during starting.

Another object of the invention is to provide an alterhating current motor capable of withstanding sustained and frequent starting periods.

Another object is to increase the starting and running etiiciencies of alternating current motors.

Another object is to reduce the cost of alternating current motors without reducing the horsepower output thereof.

Another object is to provide an alternating current motor that can be wound and made connectable for dual voltage operation and reversible operation by relatively simple means.

Another object is to provide means for reducing the ICS starting current in alternating current motors which means can be installed as original equipment or added as an improvement on existing motors.

Another object of this invention is to prolong the life and reduce the maintenance costs associated with alternating current motors.

Another object is to provide an alternating current motor in which the starting current need not substantially exceed the current in the main winding of a single phase induction motor.

Still another object is to provide a self-starting alternating current motor that does not require separate impedance or phase shifting devices, shorted or shaded windings, high resistance windings, or commutators and brushes.

This invention covers a motor having a stationary and a rotating winding, one of said windings having first and second adjacent portions and a' third phase displaced portion, and speed responsive switch means movable between a starting position in which said rst portion is connected to an AC. source and magnetically coupled to a starting circuit consisting of the second and third portions, and a running position in which said first and second portions are connected to the source.

These and other objects and advantages of the present invention will become apparent after considering this specication in conjunction with the accompanying drawings.

n the drawings:

FiG. i is a schematic drawing showing a motor embodying the teachings of the present invention,

FIC. 2 is a schematic wiring diagram of the electrical circuit for the motor shown in FIG. l,

FIG. 3 is a schematic wiring diagram showing a modified form of the motor of FIGS. l and 2, and including in phantom outline an optional feature which can be added thereto, and

FIG. 4 is a schematic wiring diagram sho-wing another modified form of the motor oi FIGS. l and 2.

Referring to the drawings by reference numbers, the number l@ in FG. l refers to a motor which has a stator i2 and a rotor i4. The stator l?. has thre windings mounted thereon. These windings are divided into separate portions and are designated as windings i6, lid and 2d. Although FIG. l shows a four-pole motor construction this invention is not intended to be limited to four-pole motor constructions but may be used with motors having any number of poles. Furthermore, although FIG. l shows the stator 12 having three separate stator windings in, i8 and 2@ and the rotor ist having one rotor winding 22, this invention is not intended to be limited to this particular arrangement as either the stator or rotor may be rotatable and the so-cailed stator windings can be mounted on either the rotating or stationary member depending upon the particular requirements of the motor.

FiG. 2 is a schematic wiring diagram of the motor 10 in FIG. 1 and sho-ws the stator windings connected to an alternating current source 24. The diagram in FIG. 2 is shown in starting condition with power leads Li and L2 connected across stator winding i6. The lead Li is connected to one end of the stator winding i6 at terminal 2o and also to a stationary switch contact 28 located on a speed responsive `switching device 3'3. The switch 3d may be a mechanically operated speed responsive switch of a known type or it may -be a relay device (not shown) which is responsive to speed changes as reflected by voltage or current changes in any part of the motor circuit. The stator winding 18 is magnetically coupled to the stator winding i6 and acts like a transformer secondary during starting operation. One end of the winding 1S is connected to a movable switch contact ing device and t opposite end of the winding is connected to pot/er lead terminal 34. rthe main winding ,le is also connected to the terminal 34. Ffhe main winding may optionally be cross connected to stator winding i8 at intermediate points by one or riore jumpers 36 `as shown in dotted lines in FIGS l and 2. The jumpers 36 are provided to connect portions of the main primary and secondary windings le and iS in parallel. Preferably the jumpers are connected to equipotential points on the windings le and running conditions so that little or no current will flow through the jumpers during running connection. ln the starting connection, however', it is expected that current will flow through the jumpers. The purpose of the jumpers is to increase `the starting curr-ent and starting torque of the motor in about the same ratio by connecting preselected portions of the windings En and le in parallel. This reduces the effective impedance of ties: windings as connected across the source and also as connected in the starting circuit. Therefore, by this arrangement more starting current and torque can be obtained than would otherwise be possible. The starting current and starting torque can be further increased by using a relatively low impedance starting winding 2li. By changing the location of the connection of the jumper, the starting characteristics can also be changed. lt should also be noted that the jumper as sho-wn in FlG. 2 connects the `main winding portions i6 and 1S as an equivalent t connection wherein the parallel connected portions forrn one leg thereof. Por dual voltage connections only one portion of winding lr6 is cross connected to winding by jumpers 3o and when jumpers 36 are optionally selected the separate winding portion between the jumper connections and the terminal 34 may :be an equivalent single winding.

A normally closed switch contact 38 engages the movable contact 32 during starting operations and is connected to one end of the stator winding 2li. The winding Zu has its opposite end connected to the terminal 3d. As shown diagrammatically in PEG. l the winding Ztl is mounted on the stator `in an angularly displaced position relative to the windings lr6 and i8.

The rotor winding 22, is shown as a closed winding and operates like a squirrel cage winding on a conventional induction motor.

In the starting position, as described, the input voltage is impressed across the winding .lo and winding le a ts as the primary of a transformer being magnetically coupled to the winding 13 which acts as the transformer secondary. At standstill the inductive coupling between the windings lo ont. 22 has a relatively low impedance and causes considerable leakage reactance. The coupling between windings lll and ill, however, eiects a current ilow in the starting winding Ztl which is at this time connected in series with the winding i8. Since winding is positioned on the stator l2 at a phase angle relative to the windings 16 and le (FIG. l), and since the voltage induced in the winding i3 by winding is approximately 180 degrees out of phase with the vol .ve across the winding le, the current flowing in windings i8 and Ztl is out of phase with the current flowing in winding lo. Furthermore, a certain amount of leakage reactance due to the inductance of the windings yand ,lo is also present and causes the current (or linx) produced in the starting Winding 2f; to lag behind the current (or flux) produced in the main winding i6 by an angle which is even greater than the l() degrees produced by the transformer action. The effect this leakage reactance prelerably shifts the phase of the secondary current to a position nearer 270 degrees out of phase with the current in the winding lo, and in effect is the same as a 9G degree leading current in the starting winding Ztl. This is indicated in l by showing that the rotation is from the starting pole toward a like main pole or a counteron the switchze of conductor used -c larger in cross-sccticn tional motors because nce to split the in the p 'esent motor tha the ywinding El? does not phase or produce the des f The phase shift thus established produces start is not cssential to this invention but is included because it is befor lieved more economical to utilize the winding s carrying part of the running load ythan to have windin:d idle at running speeds. When winding l is used dci .D running operation its physical location in the motor slots and its impedance should be selected so that they improve -the performance of the motor at running speed in FlG. l the relative positions of the windings ld caf it: are shown in phase for illustrative purposes only and do ,not necessarily represent the best possible locations therefor.

It is `also anticipated to further simplify the present construction by eliminating the switching device *d together and instead, where circumstances per it, connect the phase winding Ztl permanently across secondary winding 18 (FIGS. l and 2) and connect the primary winding i6 across the line.

In the past split-phase motors have not been constructed for operation on dual voltage connections, that 1s alternatively on two different source voltages such as on volts and on 220 volts. The present motor lil, however, makes such a connection possible. For dual voltage connection, the winding i6 is wound so that the several portions thereof can be connected in parallel for low voltage operation and in series for high voltage operation. If contact 28 is used and winding l?,- is connected in parallel to the winding lo during running operation, then both portions of the winding ll6 should have the same impedance. This provides a more satisfactory condition of operation than the more common practice of providing dual voltage connections for capacitor motors wherein the starting winding and a capacitor are connected across one-half of the main or running winding on the high voltage connection. In the present motor il@ the phase splitting is done solely by induction and transformer action and the characteristics are approximately the same regardless of whether it is connected for high or for low voltage operation.

The present motor construction does not strictly comply with the commonly accepted definition of a splitphase motor because it does not use a high resistance starting winding connected across the power source. Furthermore, the present motor does not fall into the general class of motors using external impedances. The' fore, since the positioning of the windings and the tive coupling therebetween provides the only means for shifting the phase in the present motor construction, the present motor might possibly be classified as a hybrid type of split-phase motor such as a high impedance start split-phase motor or leakage reactance split-phase motor.

It should also be noted that the windings ld, 1S and E@ could be tapped as for example, the starting wi ding 2li could be tapped to an intermediate point on winding itl, Winding i5 could be tapped to an intermediate position on winding lo, winding could be tapped to en intermediate position on winding llt), or the windings and i3 could be cross connected by one or more jumpers such as the jumpers 3d shown in dotted lines in T l and 2. Any one or more of these combinations could be used without changing the basic principle of operation.

accesso Furthermore, it is not always necessary to disconnect the starting winding from the winding 13 when the motor reaches a predetermined speed as noted hereinabove.

In PIG. 3 is shown a modified motor construction E@ which involves somewhat the same principle as the motor 1li except that the stator windings are arranged to start with a plurality of magnetic poles and run with a greater number of poles. For example, it can start as a two-pole motor and run as a four-pole motor which has the unique advantage of utilizing all of the windings (conductors) during the running cycle. The modified motor 50 has two sets of four stator (or rotor) windings, each set being connected in a closed loop. The rotor is not shown. One set of windings is shown in the drawing outside of the other set for convenience of illustration and does not necessarily indicate their physical location on the motor. The windings in the outer set are identified as numbers 52, 54, 56 and 58; and the associated windings in the inner set are identified by numbers 60, 62, 64 and 66. The four outer windings are connected with terminais between each pair of windings as follows: terminal 68 between windings 52 and 54, terminal 70 between windings 54 and 56, terminal 72 between windings S6 and 5S, and terminal 74 between windings 58 and 52. The inner set of windings are similarly connected with terminal 76' between windings 60 and 62, terminal 7S between windings 62 and 64, terminal 80 between windings 64 and 66, and terminal 82 between windings 66 and 6l?.

The windings 54 and 62 are inductively coupled as are the windings 56 and 64, the windings 58v and 66, and the windings 52 and 60. Each pair of inductively coupled windings such as the windings 54 and 62 are mounted at a different location on the motor. For example, the windings 54 and 62 are mounted on the motor opposite from the windings 56 and 64 and each set of said coupled windings may extend substantially half way around the motor. Likewise the windings 58 and 66 are mounted opposite from windings 52 and 6i) and are located on the motor at an angle of approximately 90 relative to the windings 54, 62, 56 and 64. With this location for the windings and with the switch 90` closed for start ing, the motor has two magnetic poles.

ri`he terminal 68 in the outer set is connected to the terminal 76 in the inner set by a jumper 84, and similarly the terminal 72 in the outer set is connected to the terminal -tt by a jumper 86. Also a jumper 87 is connected between terminals 78 and 82.

The terminal 68 is also connected to line lead L=1 and the terminal 72 is connected to the other line lead L2. The terminal 7@ on the outer loop is connected to a normally closed stationary switch contact 68 on a speed responsive switch 90, and a transfer contact 92 engages the contact SS during starting and is connected to the line lead La.

If motor Sti is a two-pole start and a four-pole run motor, then windings 54 and 62 constitute one of the main poles, windings 56 and 64 constitutes the other main pole, windings S2 and 6) constitute one of the phase displaced starting windings, and windings S8 and 66 constitutes the other phase displaced starting winding.

The switch 96* is closed during starting and opens when the motor speed reaches or exceeds a predetermined value. During starting with the switch 9d closed, the line leads Lil and L2 are connected across opposite terminals of the inner and outer loop at terminals 68 and '72 and lead Ll is also connecte-d to terminal 7i) thereby shorting winding 54. The shorting of the winding 54 unbalances the connection of the winding, and the unbalanced condition produces a phase displaced -current in certain of the windings relative to other of the windings which produces the torque necessary to start the motor as will be shown.

The unbalanced condition which is present only during starting produces a transformer action between the winding 56 which is connected across the line and the winding 64. Since the winding 56 is connected directly across D the line it acts as the primary of a transformer and also as the main motor winding and induces a current in the winding 64 which is 180 degrees out of phase with the current in the winding `56. This induced current together with the leakage reactance rand/ or inductance of the windings in the inner set produces a phase shift between the current flowing in the winding 64 and also in the windings 68', 62 and 66. This phase shift produces the starting torque. As the speed of the motor Sit increases and reaches and exceeds a predetermined value, the switch 9d opens disconnecting the line lead Li from the terminal 70'. The terminals 63 and 72 only are connected across the line and the windings in both sets are in balance. ln this position all of the windings are effective for producing the required number of running poles for the motor and the motor is in balanced condition. The particular motoi construction shown in FIG. 3 employs very little starting current and also very little starting torque but has maximum possible output and eiciency at running condition.

It should be noted that the modified motor Sil does not require any separate phase shifting means such as capacitors, reactors or resistors to produce the starting torque. Instead it relies only on the windings themselves and on the action of the switch 93. Furthermore, there is no interruption in the line current once the motor is started due to a change over from starting to running condition because terminals 68 and 72 are always connected across the line.

If it is desired to increase the starting torque of the motor Si?, this can be simply accomplished by connecting additional phase shifting circuits across the terminals 79 and 7d. Such a circuit is shown in phantom outline in FiG. 3 and consists of a capacitor 94 in parallel with a -resistor 96. lf such a circuit were used, it would effect the amount of phase shift and starting torque produced during starting operation but would have no effect at runnin-g speeds as there would be little or no voltage between terminals 73 and 74 because of the balanced connection of the windings.

In FIG. 4 is shown another form 10U of the motor l. The motor win-dings of motor 160 are connected similarly to the windings in motor 5t) and are identified by the same numbers. A different form of speed responsive switch is employed and is identified by number 102. However,

the switch 162 is connected to the motor windings in a different way than the switches already described. The switch iii?. has two ganged transfer contacts 104 and 1%, and the transfer contact 164 is connected to motor ter minal 7?, and the transfer contact 166 is connected to the motor terminal 66.

During starting the transfer contacts N4 and 166 are respectiveiy engaged with stationary switch contacts ld and il@ and in this position the motor terminal 76 is connected to line lead L1 through switch contacts i104 and Mitt, motor terminal 63 is connected to line lead L2 through switch contacts 166 and 3.10, and the motor terminal 72 is connected directly to line lead L2. Obviously, therefore terminals 68 and '72 are common during starting.

in the starting condition, as described, windings S4 and 56 constitute the main windings of a two-pole motor and by transformer action induce currents degrees out of phase in windings 62 and 64 respectively. These in duced currents are transferred to the starting windings (S2 and 60) and (58 and 66) which are positioned on the motor at a spaced angle relative to the main windings and are connected across the secondary windings 62 and 64 respectively. (Note: lIn the modified structure ttl a jumper 87 is connected between terminals 82 and 73 and a jumper M2, shown in dotted line, is optionally connected between motor terminals 74 and 32, and these jumpers connect windings 52 and 66 in parallel and also connects windings 5S and 66 in parallel. The jumper 112 can be eliminated, if desired, but if used the windings 52 and 64% can be replaced by a single equivalent winding and accesso i the windings Sil and can also be replaced by single equivalent winding.)

A phase shift is established in motor itin `between the current (or ilux) in the main windings 54 and Sd and the current (or flux) in the associated starting Circuits (011 consisting of windings 62, ed and 52, and the other of windings od, d6 and S3). This phase shift is sufficient in combination with the reactance of the windings to provide the desired starting torque. rhe direction of the phase shift is the same as in a capacitor or resistor splitphase motor, that is, the current in the starting circuits leads the current in the main windings. This is explained by the fact that the currents through the secondary winding 62 and 64 are 180 degrees out of phase with the currents in the respective primary or main windings d and Se, and the reactance of of the secondary windings 62 and 613' added to the react-ance of the starting windings produces the desired phase shift for starting.

When the motor itl@ reaches running speeds, the switch contacts idd itis transfer moving out of engagement with contacts lli@ and lili. ln so doing, the contact iisd engages a running contact M4 and connects the line lead Ll to the motor terminal 68 thereby connecting the terminals and 72 across the line and connecting the motor in a four-pole balanced condition. ln the running connection all of the windings contribute to carrying a share of the running current. ln running condition, the transfer terminal 124i is inoperative.

vin regard to the modi'iied motors shown in FIGS. 3 and 4 it should be noted that for maximum running output the ratio of the turns in `winding 5d to the turns in winding 55.- should be the same as the ratio of the turns in winding 62 to the turns in winding d4, and furthermore the total combined turns in windings 56 and 54 should equal the total combined turns in windings 62 and 64. This assumes that the conductor size used is the same for all windings. Likewise, the ratio of the turns in winding 66 to the turns in winding 6l) should equal the ratio of turns in winding 52 to the turns in windinn 58, and the total combined turns in windings 66 and 6d should equai the total combined turns in windings S8 and 52. This again assumes that all of the windings are constructed of the Sarre size wire.

Thus, it is apparent that there has been described a novel motor construction which makes use only of the inductive and reactive characteristics of the windings themselves to produce the desired starting torque and which operates in a nignly eiiicient and balanced condition during running operation, and which fullls all of the objects and advantages sought therefor. It is to `be understood that the foregoing description and the accompanying drawings have been presented only by way of illustration and example, and that changes, modications and alterations in the present disclosure, which will be readily apparent to one skilled in the art, are contemplated as being within the scope of the present invention which is limited only by the claims which follow.

What is claimed is:

l. An alternating current device comprising a stationary member having a winding thereon and a rotatable member having a winding thereon, one of said windings having a main portion, a secondary portion positioned adjacent to the main portion and magnetically coupled thereto, part of each of said main and secondary portions being permanently connected in parallel, a starting portion angularly displaced relative to the rnain and secondary portions on the associated member, an A C. source, and switch means movable between a start position in which the A.C. source is connected across the main portion and the secondary portion is connected in a closed circuit with the starting portion, and a running position in which the main, secondary and starting portions are connected in parallel across the AC. source.

2. A multi-voltage, adjustable torque leakage reactance split phase alternating current motor comprising a stator having a stator winding thereon and a rotor having a rotor winding thereon, one of said windings having a main winding portion and at least one starting winding portion, said starting winding portion being physically located on the motor at an angle relative to the said main winding portion and having an impedance that is relatively loW compared to the impedance of the main winding portion, said main winding portion having inductively coupled primary and secondary winding sections, means connecting at least one end and one intermediate location on said pritrary and secondary sections together to form a parallel connected portion of said sections, speed responsive switch means movable ybetween a starting position when the motor is operating below a predetermined speed and a running position when the motor speed exceeds said predetermined speed, means connecting the primary winding section across an alternating current source, other means connecting a portion of said secondary section including the parallel connected portion thereof in a closed circuit with said starting winding portion, said switch means in running position thereof connecting all of said secondary section in parallel with all of said primary section across the alternating current source, the inductive coupling between the primary and secondary winding sections and the inductance of said windings contributing to produce a current in the starting winding that is out of phase with the current in the primary section during starting.

3. An adjustable torque leakage reactance split phase alternating current motor comprising a stator having a stator winding thereon and a rotor hav-ing a rotor winding thereon, one of said windings having a main portion and at least one starting winding portion, said starting winding portion being angularly positioned on the motor relative to the said main portion, said main portion including mutually inductively coupled primary and secondary winding sections, means connecting together at least one end and one intermediate location on each of said inductively coupled sections to form a parallel connected portion of said sections, speed responsive sw` l means on the motor movable between a starting posit.cl and a running position in response to preselected cl in the motor speed, means connecting a portion of said primary section including the parallel connected portion thereof across a source of alternating current, means including the switch means in the starting position thereof connecting said secondary section including said parallel connected portion thereof in a closed circuit with said starting winding portion, said switch means operating to open the closed circuit in the running position thereof, 'the leakage reactance between said primary and said secondary sections and the inductance of the windings producing current in the starting winding portion that is of different phase than the current in the primary winding section.

4. A multi-voltage, adjustable torque leakage reactance split phase alternating current motor comprising a stator having a stator winding thereon and a rotor having a rotor winding thereon, one of said windings having angulariy related main and starting winding portions, said starting winding portion having a relatively low impedance compared to the impedance of the main winding portions, a rst part of the said main portion including mutually inductively coupled primary and secondary sections, and means connecting together at least one end and one intermediate location on each of said coupled winding sections, said coupled sections forming at least one pole winding group, speed responsive switch means in the motor movable between a starting position and a running position in response to preselected changes in the motor speed, means including the starting position of the switch means connecting the secondary section of the main winding portion in a closed circuit with the starting winding portion, said switch means in the running position thereof opening the closed circuit to the starting winding portion,

the current in said starting winding portion being out of phase with the current in the said primary section of the main portion, said out of phase current being produced by the leakage reactance between the primary and secondary sections and by the inductances of the windingsA 5. A multi-voltage, leakage reactance split phase alternating current motor comprising a stator having a stator winding thereon and a rotor having a rotor winding thereon, one of said windings having relatively anguiarly related main and starting winding portions, said main winding portion having rst and second mut-daily inductively coupled winding sections forming part of one pole winding group, and a third section of said main winding portion connected in series with the coupled irst and second sections to form a Y connection therewith, the phase relation of the current flowing in each of the said iirst, second, and third sections being different, means including speed responsive switch means connecting said starting winding portion in series circuit with the second section and at least part of the said third section during starting of the motor, other means connecting said lirst and third sections in series across an alternating current source, the current in the starting winding portion being out of phase relative to the current in the iirst and third sections, said out of phase condition being in part produced by the mutual inductance between the iirst and second sections, in part by the leakage reactances of the first, second and third sections, and in part the inductances of the windings.

6. A leakage reactance, split phase, alternating current motor comprising a stator having a stator winding thereon and a rotor having a rotor winding thereon, one of said windings have relatively angularly positioned main and starting winding portions, said main portion having first and second mutually inductiveiy coupled winding sections forming part of one pole winding group, and a third section at least a part of which is connected to the first and second sections forming a Y connection therewith, the phase relation of current iiowing in each of said first, second and third sections being different, speed responsive switch means on the motor movable between a starting position and a running position in response to changes of motor speed, means connecting said irst and third winding sections in series across a source of alternating current, other means connecting said starting winding portion in a closed circuit with said second and third winding sections during starting, said switch means in the runnng position thereof connecting said iirst and second winding sections in parallel and the parallel combination thereof in series with the third winding section across the source of alternating current, the current in the starting winding portion being out of phase relative to the current in the iirst and third sections during starting, said out of phase current condition being in part produced by the mutual inductance between the rst and second sections, in part by the leakage reactances of the iirst, second and third sections, and in part by the inductances of said Winding sections.

7. A leakage reactance, split phase, alternating current motor comprising a stator having a winding thereon and a rotor having a winding thereon, one of said windings having relatively angularly positioned main and starting Winding portions, said main portion having first and second mutually inductively coupled winding sections forming part of one pole winding group, and a third section at least a part of which is connected to the iirst and second sections forming a Y connection therewith, the phase relation of current flowing in each of said first, second and third sections being different due to the leakage reactances between said winding sections, and speed responsive switch means movable between a starting position when the motor is operating at less than a preselected speed and a running position when the motor speed exceeds said preselected speed, means connecting said iirst section in series with said third section across the source of alternating current, and other means including the starting position of the switch means for connecting said starting winding portion in a closed circuit with said second and said third winding sections to load said sections during starting and thereby substantially increase the aforesaid leakage reactances, the current in said starting winding portion being out of phase relative to the current in the irst and third sections, said out of phase current condition being in part produced by the mutual inductance between the first and second sections, in part by the leakage reactances of the first, second and third sections, and in part by the inductances of said winding sections.

8. The motor defined in claim 7 wherein said switch means includes means for connecting said first and said second sections in parallel at running speeds.

9. A multi-voltage, adjustable torque leakage reactance split phase alternating current motor comprising a stator having a winding thereon and a rotor having a winding thereon, one of said windings having a main portion and at least one starting winding portion, said starting winding portions being angularly positioned relative to said main portion, said main portion having mutually inductively coupled primary and secondary winding sections, means connecting together one end and one intermediate location on said primary and secondary sections, speed responsive switch means movable between a starting position when the speed of the motor is below a preselected speed and a running position when the motor speed is greater than the preselected speed, means connecting said primary section across a source of electric energy, other means including the starting position of the switch means connecting said secondary section in a closed series circuit with said starting winding portion, the running position of said switch means disconnecting the circuit to the starting Winding portion and connecting said secondary section in parallel with the primary section across the energy source, the current in said starting winding portion during starting being out of phase with the current in the primary section in part because of the leakage reactance between the primary and the secondary sections and in part because of the inductances ofthe windings.

References Cited in the tile of this patent UNITED STATES PATENTS 1,894,124 Schaefer Jan. 10, 1933 2,262,870 Veinott Nov. 18, 1941 2,697,809 Hutchins et al Dec. 21, 1954 2,864,986 Hutchins et al Dec. 16, 1958 

